NO. I BLACK FLIES OF GUATEMALA DALMAT l6l 



(pi. 24, fig. 48) with numerous (about 35) teeth, both long and short, 

 extending along its entire length; lateral plate long, somewhat rec- 

 tangular in shape, wrinkled, slightly sclerotized. 



Female (pi. 30, figs. 163-165, and pi. 35, fig. 263). — 2.5 mm. long. 



Head : Dichoptic. Eyes very dark reddish brown ; fronto-ocular 

 triangle very small, its base 1.5 times its height. Antenna 420 fi long, 

 ii-segmented, slightly tapering; segment 3<i-f2, 3 = 4-f5> 3 = ii; 

 scape and pedicel light brown, flagellum dark brown to black. Palpi 

 black. Frons black, white-pruinose, with one irregular row of black 

 hairs along the lateral margins. Clypeus black, white-pruinose, ir- 

 regularly covered with short black hairs. Occipital region black with 

 a few long black hairs. Comuae of buccopharyngeal apparatus sclero- 

 tized, hornlike, sharply pointed ; median space hyaline, with long thin 

 teeth on lateral margins. 



Thorax : Mesonotum velvety black, with 2 very wide longitudinal 

 stripes of white pruinosity which extend, one on either side of midline, 

 from the anterior margin to the white pruinosity of the prescutellar 

 region ; bands widest at anterior margin, with more than the width of 

 one band between them ; lateral margins yellow, with white pruinosity ; 

 long, narrow, brilliant-yellow, scalelike hairs along the periphery and 

 on the longitudinal bands ; short black hairs on all of mesonotum. 

 Humeral angles yellow, with white pruinosity. Scutellum dull yellow, 

 with a few long black hairs and with some yellow scalelike hairs. 

 Postnotum velvety brown, with white pruinosity. Pleura yellow to 

 brown, with white pruinosity. Stem of halter light brown, the knob 

 yellow. Wings, 2.7 mm. long and 1.2 mm. wide; relation of body 

 length to wing, 1:1.1; Sc pilose along basal two-thirds; Ri pilose 

 and spiny on distal half ; R2+3 pilose except for very short basal section ; 

 Cug arcuate ; discal cell absent. 



Legs: Leg i, length, 2.6 mm.; coxa, trochanter, and femur light 

 brown; basal four-fifths of tibia tan, the apical fifth dark brown; 

 tarsus black. Leg 2, length, 2.4 mm. ; coxa brown ; trochanter light 

 brown ; femur light brown with small dark-brown apical ring ; tibia 

 tan on basal two-thirds, dark brown on apical third ; basal half of 

 basitarsus tan, apical half black ; tarsal segments 2-5 black. Leg 3, 

 length, 2.9 mm. ; coxa dark brown ; trochanter light brown ; femur 

 light brown on basal third, dark brown on apical two-thirds ; basal 

 half of tibia light brown, apical half black ; basal two-thirds of basi- 

 tarsus and basal half of second segment tan, the remainder of these 

 segments, as well as all of segments 3-5, black ; relation of basitarsus 

 to second segment, 3.9 : i ; calcipala well developed, reaching only 

 halfway to pedisulcus ; pedisulcus well developed at middle of second 

 segment; claw without tooth or spur (pi. 35, fig. 263). 



